Sunday, December 30, 2012

December to finish colder and snowier than normal..

December 2012 will finish colder and snowier than normal in Winnipeg, capping off what had been a record warm year through the fall. December will finish with an average monthly temperature of -14.7C at YWG airport, or about 1.2C colder than the normal* December average of -13.5C (1981-2010 normal - see note at bottom of post) Two cold spells around the 7th-13th and over the Christmas holidays brought the monthly average below normal, the third straight month with below normal temperatures. December snowfall of 32 cm (as measured at my site) was above the December mean of 19.8 cm, and brought the seasonal snowfall total so far up to 75 cm in the city.. almost matching last winter's entire snowfall total (80 cm) Normal seasonal snowfall in Winnipeg is around 110 cm.

For the year, 2012 will end up with an annual average of +4.6C in Winnipeg, some 1.7C above normal* and the 5th warmest calendar year on record since complete records began in 1873. 2012 was on pace to be the warmest calendar year through October, but a colder than normal finish dropped the year down to 5th place honours.

Normal* ........... +2.9C (based on 1981-2010 average)
normal annual temperature over entire period of record is 2.2C (1873-2012)

*NOTE: Rob's Obs will be using 1981-2010 normals from now on. These are the updated 30 year normals that replace the "old" normals which used the 1971-2000 averages. EC is still using the 1971-2000 normals, but plans to move to the updated 1981-2010 values soon. I will have more details on this in a later post.

24 comments:

Wow. What the heck is going on at YBR? The hourly data was 10C too cold on Dec 24, and now I see the daily min temps were also frigid for 4 days running from Dec 24 to Dec 27th, having no relation to the hourly data.

Examples: The daily min temp on Dec 26th was -42.6 C! But the coldest hourly temp only hit -29.8 C. On Dec 27th the observer estimated a daily min of -39.5 C, but the coldest hourly temp was only -22.4 C, 17C warmer!

Crazy. Pretty soon we won't have any observations worthy of calling climate data.

You're right.. some strange issues with that YBR station. I see that it went over to a NavCanada autostation as of Dec 6th.. so I suspect it has something to do with the NavCanada setup. The co-located YBR RCS site (which is an EC autostation) shows no such temperature issues.

Not at all happy with the degradation of climate data that we're seeing.. especially with the lack of quality control, and the loss of station ownership to NavCanada. NavCanada has certain needs for weather data, but accurate climate data certainly doesn't appear to be one of them.

Unofficially, YWG airport recorded 436 mm of precipitation (rain and melted snow) in 2012. Of that amount, about 375 mm was mainly rain between March 1st and Oct 31st. This amount is a bit on the low side compared with other city locations, including my station which recorded about 30% more rainfall (about 480 mm) between March 1st-Oct 31st compared to the airport site. The airport often seems to have a bit of a dry bias, likely because of its more exposed and windier location which can reduce precip catch in the rain gauge.

Sadly, that precip amount of 436 mm is hardly worthy of ever being called 'official'. A dry bias was prevelent in late Feb and early March. For example, somehow 10-12 cm of snow on March 2 melted to only 1.0 mm of water, giving a snow-water ratio higher than 100:1! Very suspicious.

Looks like the coldest temperature of 2012 in Winnipeg was -29.0°C on December 24. This is only the second time since records began (1872) that Winnipeg has not hit -30°C in a calendar year. The only other time that we didn't hit -30°C was 1931 with a yearly minimum of -29.4°C. That means this year's minimum of -29.0°C is also the warmest yearly minimum on record.We have now been 676 days (including today) without hitting -30°C. Let’s see how much longer the streak will go in 2013…

Good observation on the -30c stats, JJ. Note also that in 1931, the observing site in Winnipeg was at St John's College close to downtown, not at the airport site. If the observing site was at the airport location in 1931, I'm pretty sure it would have measured a -30c reading that year given its more rural setting. Suffice to say, this is the first time since records began at YWG airport in 1938 that Winnipeg has not recorded a -30c reading all year. Great stat!

Adam.. The dry bias at YWG airport seems to be more evident over the past decade or so when they switched to a weighing type precip gauge. This is especially true for frozen precip (snow) after they stopped human observations. I can't say for sure though unless I did a more in depth analysis on precip readings over the past 30 years vs gauge type. The lack of thorough quality control on the data since 2007 also puts the numbers in question.

I see the issues with YBR is still ongoing at least with the daily stats. It shows yesterday's high as being +2.5C which we know is totally false and should not even show up in the stats.

And then there's Carman. last night it had temps about 5C or so colder than everywhere else at - 28C but then temps rose all the way to - 10C by 8AM this morning, which is about 18C rise in 9 hours...that seems rather suspicious. And now temps fell back to about -12C by 10AM and have stayed steady since.....very strange.

Carman's rise to -10C this morning looks reasonable based on surrounding area temps. As noted, it was colder than surrounding areas last evening, but 5C is not totally out of line on a calm clear snow covered night. Note also that Carman is an EC autostation which seem to be more accurate than the NavCanada stations.

As for YBR, I don't know what the heck is going on with that station. A daily high of +2.5C yesterday when the temperatures were below -20C all day? Obviously some serious issues with the data processing with that site. Again, only dedicated quality control of climate data will ensure that such erroneous data is not entered into the climate archives. And that's the obvious cases. What about the more subtle erroneous data that can easily get through the cracks without notice?

In my short time as a contract airport weather observer I saw all matter of problems (sleeping through obs, making up data, too lazy to walk outside for obs, erroneous coding, etc, etc). I was offered the job of managing the Calgary station, for less than $10/hour. I turned it down and the contractor said he'd put one of the new trainees in the position.

There are some dedicated observers out there (and some that were fired from McDonald's, literally), but not like when EC used to staff the stations. The training is good (at least mine was) but there's no follow-up, and no incentive to impress the boss because it's a dead end job.

Something has to change. I wrote letters to EC about this in the 90's, but it's only got worse now with NavCanada and the lack of a QC program.

Clipper moving through interlake bringing band of snow across RRV and SE MB this evening, while SW MB taps into a nice westerly flow of Pacific air that has raised temps up to -1C at Melita. As clipper moves across Winnipeg overnight, milder air will occlude southwest of us, although we may pop up to -6C overnight as winds shift into the NW before we cool off again during the day Wednesday. A stronger westerly flow of Pacific air may get Winnipeg above the -5C mark by late Thursday.

With the dry bias at the airport the past decade, 2010 likely was in fact the wettest year ever. Most parts of the city had over 700 mm of rain through the year, and this does not even include snowfall. It's very unfortunate that we did not get good precip. amounts that year from the airport as it makes 2010 look a lot less significant that it really was.

As you can see, a workout, which includes afterburn exercises, is a win-win all around [url=http://www.cosylouboutinshoes2013.co.uk/]christian louboutin[/url] Prices suiting your budgetThe best thing about charleston makeup artist is that it suits every pocket [url=http://www.thomassaboonlineoutlet.co.uk/]thomas sabo uk[/url] So, you have planned to open a new office? You must be busy in figuring out the various requirements in the office [url=http://www.2013thomassaboonline.co.uk/]thomas sabo sale[/url] Therefore, higher cash conversion cycle numbers can be better than lower cash conversion cycle numbers., a killer combination that might be in hot need for certain fields, like education, government consulting, or finance [url=http://www.2013tomsshoes-outlet.com/]cheap toms shoes[/url] From filing products to industry leading ergonomic office chairs, full service companies allow shoppers to purchase everything needed for their business quickly and easily [url=http://www.2013tomsonsale.com/]toms shoes outlet[/url]